Various plastic films coated and baked on aluminum foil were individually immersed in a model fruit-flavored aqueous solution in sealed glass jars. Every solution was stored at room temperature for two weeks. Then the films were immersed in diethyl ether for one day to extract volatiles sorbed in the films. The volatiles were quantitatively analyzed by GC-MS. As a result, epoxy-acryl films sorbed various components well because of having both hydrophobic and hydrophilic parts. Vinyl films sorbed the components a little, but sorbed selectively terpene hydrocarbon component well because of affinity for hydrophobic components. Epoxy phenol films showed middle tendency of epoxy-acryl films and vinyl films. As for saturated normal chain aldehyde components, the sorption ratio increased with increasing carbon numbers.

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The gel formation of porcine globin prepared by the acid-acetone method and the acid hydrolyzates of the resulting globin were investigated. (1) Globin dissolved in acidic solution below pH 4.0 and in alkaline solution above pH 10.0, and was almost insoluble in the pH 7.0 to 8.0 region. (2) Globin gel was formed in the pH range 2.0-4.0 and 10.0-11.0, and at a globinconcentration above 7%. (3) Though globin formed the gel when citric acid was added in the range of 0.02M to 0.2M, the further addition of the acid, 0.4M to 2.0M, inhibited the gel formation. However, the transparent gel was formed when the solutions whose gel formation was inhibited were allowed to stand at 30°C for 10days. In the case of acetic acid and phosphoric acid, the effects of these acids on gel formation was similar to that of citric acid though acid concentration and the values of gel strength of the gel formed were different from those of citric acid, respectively. The hydrolysis of globinin these acids and SDS -PAGE of the resulting hydrolyzates were carried out. When the hydrolysis was done by these concentrated acids, the protein band of about 15 kDa which is thought to be globin was pale and the bands below 15 kDa, on the contrary, were dark. From the results, it is thought that the hydrolyzates produce a marked effect on the gel formation of globin. In addition, it was suggested that the proportion of globin to the hydrolyzates was closely correlated with the gel strength of the gel formed.

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Tofuyo is a unique fermented soybean protein food in Okinawa Prefecture, Japan. In this study, changes in soybean protein and some nitrogen compounds of tofuyo prepared by Aspergillus oryzae during fermentation were investigated. Crude protein content decreased during a ripening period. Digestion of soybean protein during fermentation was examined by slab polyacrylamide gel electrophoresis. Some polypeptide bands of soybean globulin such as α'-, α-, β-subunits in β-conglycinin and acidic subunit in glycinin in the water-insoluble fraction of tofuyo disappeared after 3-month ripening, but that of basic subunit in glycinin still remained. It was found that the maturation of tofuyo proceeded with the phenomenon that soybean protein was hydrolyzed by proteases in the soak (moromi). The main components which formed the body of tofuyo consisted of basic subunit in glycinin and other polypeptides (Mr.32kDa, 10-13kDa). The ratio of water-soluble nitrogen, 4% -trichloroacetic acid-soluble nitrogen or 75%-ethyl alcohol-soluble nitrogen to the total nitrogen reached to 38.8, 34.3 or 19.9% after 3-month ripening, respectively. Amount of total free amino acids in the tofuyo increased during maturation, and glutamic acid, aspartic acid, alanine and proline were contained at a high level.

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Heat treatments were done by increasing the temperatures of egg white gel from 20°C to 85°C for 45min (raising slowly) and for 27min (raising rapidly). All the scores for the hardness, elasticity and viscosity of the shell egg white gels prepared in 1%NaCl solution were higher than those of the shell egg white gels treated in deionized water. All the rheological parameters of the shell egg white gels treated with rapid temperature rise were lower than those of the gels treated with slow temperature rise. The gels formed by rapid temperature rise were composed of spindle-shaped clusters, about 1.5 μm in length, and 0.5μm in width, but the gels by slow temperature rise were made up of massive aggregates. The structures formed in heated shell egg white gels may be responsible for elasticity and viscosity of egg white gel, but not for hardness.

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Globin was hydrolyzed by 0.8M citric acid at 95°C for 15min. After the resulting hydrolyzates were dialyzed against running water for 24h, they were powdered by using a spray drier. The hydrolyzates were more soluble in water than globin at pH values from 2.0 to 11.0, but their solubility showed the lowest value in the pH 6.0 to 7.0 range, whereas that of globin was lowest in the pH 7.0 to 8.0 range. The hydrolyzates formed gel at a protein concentration above 3% and in the pH 2.0 to 4.0 range. The gel of the hydrolyzates was transparent and showed high gel strength compared with that of globin under the same conditions. The mixture of the hydrolyzates and agar formed gel at pH values from 2.0 to 8.0 though the gel formation of agar was difficult below pH 3.0. In addition, the gel strength of the gel was synergistically enhanced by mixing these substances. However, the mixed gel became opaque at neutral pH value. The mixed gel of the hydrolyzates and gelatin showed similar gel properties to that of the hydrolyzates and agar.

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For the quality evaluation of leaves of Gymnema sylvestre R.Br. and the extract, total gymnemic acids was determined by HPLC analysis of gymnemagenin, which was the main sapogenin obtained from a mixture of gymnemic acids by alkaline saponification followed by acid hydrolysis. It was found that total gymnemic acids content in four specimens of leaves imported from India was 3.9-4.6%, and that in seven commercial samples of leaves extracts was 3.9-9.6%.

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In order to clarify the mechanism of gelatinization of starches inside cotyledon cells of adzuki bean (Vigna angularis), gelatinization of starches inside cells and isolated starches heated previously for one hour at a temperature of 60 to 90°C was examined by differential scanning calorimetry (DSC) and birefringence. DSC thermograms of cells showed a endothermic transition with peak temperature at about 70°C which trailed a shoulder up to 98°C. The pre-treatment of cells at 60 and 65°C caused an increase in the onset (To) and peak (T_p) temperatures, and a sharpening of the peak. An increase in T_o and T_p, and a decrease in the gelatinization enthalpy(ΔH) were observed with a further increase in pre-treatment temperature. These changes in the endotherm on a lower temperature side by the pre-treatment were nearly identical to those for isolated starches. The shoulder of the endotherm on a higher temperature side was not affected by the pre-treatment at temperatures below 80°C. The effect of pre-treatment temperature on loss of ΔH agreed with that on loss of birefringence for both starches inside cells and isolated starches. The losses of ΔH and birefringence for starches in side cells were suppressed compared to those for isolated starches by the pre-treatment at 65 to 80°C.

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Glutaminase from Bacillus subtilis sp. was immobilized on a magnetic support (MC 4 P) composed of partially deacetylated chitin (PDAC), chitosan and Fe₃O₄. The immobilized glutaminase in concentrated salt solution was more stable than glutaminase in the free form at acidic pHs and at a high temperature (60°C). The same tendency was observed even in ethanol saline solution (ethanol concn. 20%, NaCI concn. 16%). When the reaction mixture of 1.5% glutamine solution containing 16% NaCl was supplied to a column reactor at a space velocity of 0.68h^-1, the period of fifty percent decline of initial conversion rate of the immobilized glutaminase required 169 days at 40°C, 114 days at 50°C, and 100 days at 60°C, but the conversion rate at 30°C did not change after 180 days. Glutamic acid (4.4-5.5mg/ml) was produced from glutamine in immature soy sauce moromi filtrate through the bioreactor at a space velocity of 1.0h^-1. This bioreactor system worked well over a 35 day period. The immobilized glutamine was supplied repeatedly to different koji hydrolysates and recovered each time by exposure to a magnetic field. By this method glutamic acid (3.4-3.6mg/ml) was produced during a 72 h period involving four recyclings of the enzyme.

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Freeze-thaw resistance of Torulaspora pretoriensis YK-1 in doughs containing 30% and 5% sucrose was higher than that of Saccharomyces cerevisiae FL 2209 isolated from commercial compressed yeast, but both strains were susceptible to freezing injury in the dough without addition of sugar. From these observations, breadmaking was performed by the frozen-dough method. As compared with FL 2209, both elongation of proof time and decrease of specific volume by the storage with freezing were suppressed in the dough containing YK-1. Comparing with the baked goods without freezing, specific volume of those made with YK-1 was higher than 95% and 75% when storage period was less than 21 days in sweet bread and 7 days in white bread, respectively.

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Sensory evaluation is recognized as a useful and indispensable means in food research. To understand the present state of sensory evaluation in food science and technology in Japan, fifty five (55) research papers reporting sensory evaluation data, published in Vols.37 (1990), 38 (1991) and 39 (1992) of Nippon Syokuhin Kogyo Gakkaishi (this journal), are reviewed. Comparing with those (77 papers) of Vol.57 (1992) of Journal of Food Science (JFS), several distinctive features can be pointed out. In addition to tests of "analytical" and " affective" types, two major classifications of sensory evaluation, tests of "grading" type have been equally adopted, especially in this journal. In any type of tests, the so-called "rating-scale" method has been most frequently applied both in this journal and in JFS. Paired comparison is used in some reports in this journal, but never in JFS. On the other hand, magnitud estimation is used in some cases in JFS but never in this journal.

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Reviewing research papers reporting sensory evaluation data, published in recent Nippon Syokuhin Kogyo Gakkaishi (this journal) and Journal of Food Science (JFS), application fields of sensory evaluation are grouped into 12 categories. Those are; (1) comparison of nominal classifications (such as species, brands, etc.), (2) pre-harvest conditions, (3) ingredients, additives and formulations, (4) processing conditions, (5) storage studies, (6) cooking conditions, (7) description of test products, (8) quality control, (9) subjective-objective correlations, (10) sensory identifications, (11) fundamental sensory properties and (12) terminology and methodology. In this journal, most papers are concerned with the categories (1) or (4) and no paper directs attention to the categories (2) and (11). In JFS, most papers are related to the categories (3), (4) or (5) and the categories (6)-(12) are least concerned. Correspondence between the application fields and the types of sensory evaluation is summarized and discussed.

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As rating-scale method is the most frequently used both in Nippon Syokuhin Kogyo Gakkaishi (this journal) and in Journal of Food Science (JFS), its terminology (Japanese) and format are reviewed. Although many terms (Japanese) partly synonymous with "rating-scale" are described in literatures and textbooks, only two terms, "(structured) category scale" and "(unstructured) line scale", are sufficient. All of scales in this journal are category scales, and about 20% of scales in JFS are line scales. The number of attributes in analytical-descriptive tests is larger in JFS than in this journal, in most cases. The most frequently used category scales consist of 5-point scales, and 7-point and 3-point scales are used in some cases in this journal. In JFS, 8-0-point scales are commonly used. Data are analysed as interval scale in most papers and "consensus score" is also reported in a few cases.

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